Introduction on primary immunodeficiency diseases

Primary immunodeficiency diseases (PIDs) are a heterogeneous group of disorders with defects in one or more components of the immune system. Primary immunodeficiency diseases could suffer from a variety of clinical manifestations, including recurrent, severe or unusual infections, autoimmunity, and lymphoproliferation/malignancies. Primary immunodeficiencies constitute a large group of diseases, affecting the development of the immune system, its function, or both. The number of known PIDs has been increased considerably over the last decade, while more than 300 different types have already been explained. Although the number of patients diagnosed with PIDs is growing, health care workers still know little about these disorders. Thus, many patients are diagnosed late; many cases suffer from complications by chronic infections, irretrievable end-organ damage, or even death before the definitive diagnosis is made. Timely diagnosis and appropriate treatment remain the keys to the successful management of patients with PIDs. Keywords: Primary immunodeficiency diseases, Infections, Autoimmunity, Malignancie